The invention relates to a circular saw machine with a saw blade which is retained, movable forward and backward in its rotation plane, for the sawing process; with a drive shaft for the saw blade, movable back and forth together with the saw blade; and with at least one rearward and one forward saw blade guide for the two side surfaces of the saw blade. The saw blade guides respectively have at least one contact surface to abut on the respective side surface of the saw blade.
Circular saw machines of this type are widely used in mass production of materials. Here steel rods are mostly sawn into individual sections, on which the highest accuracy requirements are placed in narrow tolerances relating to cut length, angularity, parallelism, and surface condition of the cut surfaces.
Thus the requirements on the accuracy of cut of the circular saw machine are particularly high in circular saw machines of the kind mentioned at the beginning. The already restricted tolerance regions on workpiece measurements are further restricted by quality assurance measures such as for example as regards the property “machinability” of the saw cuts.
Evidently, the saw blade is now the unstable component of a circular saw machine. Particularly with increasing wear of the saw blade, it tends to deflect obliquely during sawing. Furthermore, axial vibrations of the saw blade sometimes lead to inexact dimensions of the sawn blanks.
For this reason, it has already become customary for some time to guide the two side surfaces of the saw blade as close as possible to the teeth by means of a forward and a rear saw blade guide, in order to prevent oblique pulling and vibrational movements. This saw blade guidance has of course to be made stable and highly accurate, in order to attain the desired effect. Furthermore, in order to attain a certain wear resistance, respectively at least one contact surface, which is provided with hard metal deposits or with ceramic deposits, has to be provided for the corresponding side surfaces of the saw blade. The reduction of wear phenomena finally acts in its turn to increase the accuracy of the saw blade guidance and thus of the blank.
Now it is often desirable to saw different workpiece diameters. This is possible, though, only to a limited degree with one and the same saw blade. Thus for a clean cut, workpieces of different sizes as a rule need a different saw blade diameter with a different tooth division. However, because of the above-described requirements on the tolerances of the blanks, the saw blade guidance is up to now accurately designed for a given saw blade, so that numerous circular saw machines are needed if it is desired to saw workpieces of different diameter.